Eclipse Error

I have been using Eclipse SDK 3.0.1 on win98 after installing j2sdk 1.4.2_19 for nearly 2 months and practised a number of codes. Suddenly, one day it started giving the following error
" Could not find the main file. The system will close"

2. Thinking, perhaps, that the Eclipse file has gone corrupt, I deleted it and copy/pasted again from the CD. Thereafter whenever I tried to start Eclipse, it gives out the following error and does not open.
"An error has occurred. See the log file i:\02( or l:\02 or j:\ 02 I cannot make out)

3. A very interesting phenomenon is that WHEN I OPEN IT FROM CD ROM, IT WORKS FINE AND I CAN RUN ANY CODE.